The invention relates to a circuit arrangement, comprising a circuit and means for indicating a circuit condition governing its service life.
It is known, inter alia from German Offenlegungsschrift 25.34.668, to provide passive or active components with an external layer whose color is temperature-dependent or which exhibits a permanent discoloring at a given temperature.
Any short-circuiting or overloading can be detected on the basis thereof. However, the components need be regularly inspected visually in order to check whether short-circuiting or overloading has occurred.
Furthermore, from British Patent Specification No. 2,195,185 it is known to provide an integrated circuit with test means whereby the condition of the integrated circuit can be tested, the test result (the condition of the integrated circuit) being provided via an output pin. Said test means indicate whether a tested integrated circuit operates correctly or not. However, expensive, complex electronic systems may break down at inconvenient times. If no (expensive) back-up system is provided, incredible disruptions can occur in the services provided by the relevant systems, for example in electronic payment systems or in computer-controlled vessels, airplanes, air traffic control systems or in chemical installations. The foregoing is undesirable, especially if repair times are unacceptably long.